Therapeutic gases, including oxygen, anesthetic agents, and the like, are commonly administered to medical patients during treatment. The therapeutic gases may be administered to the patient through a mask that covers the patient's nose and mouth.
Some therapeutic gases pose well-known health risks to medical workers and patients. For example, medical workers exposed to anesthesia could lose consciousness or die as a result of the exposure. Further, even small amounts of anesthesia inhaled by medical workers could diminish their capacity to provide competent care to patients, thereby jeopardizing the safety of the patients under their care.
Patients may continue to exhale residual therapeutic gases even after delivery of the therapeutic gases has ended. In turn, the residual gases exhaled may be of sufficient quantity to pose the aforementioned risks to the safety of medical workers and other patients if not properly scavenged. Thus, there exists a need for scavenging and control of therapeutic gases exhaled by medical patients.
U.S. Pat. No. 6,357,437 (“the '437 patent”) describes a pliable medical mask with an oxygen port and a recovery port extending through an upper portion of the mask. The recovery port in the '437 patent is attached to an evacuation assembly including openings that are in fluid communication with the surrounding area. The '437 patent states that the channels through the evacuation assembly allow waste gases to leak into the surrounding area. Further, the oxygen port and the recovery port in the '437 patent are free to pivot at their respective mask attachment points, given their independent arrangement and the flexible nature of the mask shell, thereby making it difficult to maintain effective relative positioning between the ports within the mask.
U.S. Pat. No. 7,114,498 (“the '498 patent”) describes a medical face mask including a shell that is fabricated of a flexible material, and a fresh-gas inflow tube and an exhaust-gas outflow tube, both of which are connected to an upper nasal portion of the mask. However, clinical use of such a mask has revealed that typical central vacuum systems may not provide sufficient scavenging potential to prevent leakage of exhaled gases from the mask into the surrounding area.
Accordingly, there exists a need for an improved mask that delivers therapeutic gases to medical patients and scavenges exhaled gases away from the surrounding area.